The first stereoselective synthesis of the specific EP1 receptor agonist, 16,16‐dimethyl prostaglandin E21, is described. The key intermediate 3 was obtained from the E‐allyl alcohol 6 via Sharpless epoxidation followed by stereospecific transformations to the γ‐iodo vinyl compound 3. Two component coupling of 2 and 3, using the dilithiocyanocuprate technology, gave the 1,4‐addition product. Mild desilylation